Class 752.6 was built originally for Italian customer, but they desiced to not buy them, so our biggest private freight operator took an advantage of this. 752.6 has engine from czech class 771, instead of gogglers 753.7 with CAT DITA family engines.
@ter 753 was original class for all rebuilds (former T478.3), Some of them were converted to 750 by changing steam heating to electric one. For private users was possibility of 753.7 (Caterpillar E-Dita) or 752.6 (K6 S310 DR from class 771 - ex T669.1). Some of it were sold to Italy and also 752.6 were intented to, but Itaian customer decides to reject the contract, so former OKD Doprava (now it´s AWT) bought´em. Maximum speed is the same and also the drivers booth is just like in 753.7.